In September 2005, a senior Wal-Mart lawyer received an alarming e-mail from a former executive at the company’s largest foreign subsidiary, Wal-Mart de Mexico. In the e-mail and follow-up conversations, the former executive described how Wal-Mart de Mexico had orchestrated a campaign of bribery to win market dominance. In its rush to build stores, he said, the company had paid bribes to obtain permits in virtually every corner of the country.

It’s a lengthy, fascinating, and thoroughly-reported exposé on how Wal-Mart executives paid off local politicians and planning officials and then obstructed an internal investigation. The illegal bribes were effective: Today, one in five Wal-Mart stores are in Mexico.